1. Technical Field
The present invention relates to an ink jet textile printing ink composition, an ink set including the ink composition, and a printing method using the ink set.
2. Related Art
For printing an image on a fabric or the like, there have been used textile printing methods such as screen printing, roller printing, rotary screen printing, and transfer printing. These textile printing methods are, however, not suitable for high-mix low-volume production in cost terms and are difficult to readily or rapidly respond to diversifying fashion trends because these methods require that an expensive screen frame, engraved roller, transfer paper, or the like be prepared every time the image design is changed.
In order to eliminate such disadvantages of the known textile printing methods, there has been developed an ink jet textile printing method (hereinafter may be referred to as ink jet textile printing) that is performed by reading a sample image with a scanner, processing the image with a computer, and printing the processed image by an ink jet printing method. Ink jet printing methods are a technique for forming a high-definition and high-quality image by ejecting droplets of an ink from an ink head onto a printing medium, such as paper or fabric, by a relatively simple and low-cost mechanism. By using such an ink jet printing method, high-tonality images can be rapidly formed without plate making required for the known textile printing. Accordingly, the ink jet printing method can shorten delivery time and can be applied to high-mix low-volume production, for example. Also, ink jet textile printing uses only an amount of ink required for forming the image intended and thus has environmental advantages in that, for example, waste ink can be reduced compared with the known textile printing such as screen printing.
Ink jet textile printing inks contain a dye, such as a direct dye, an acid dye, or a reactive dye. Reactive dyes are one of the newest dyes of history. Reactive dyes dye fabrics by a covalent bond that has the highest binding energy and is most stable of the linkages between fabrics and dyes, accordingly providing a significantly high wet color fastness. Also, reactive dyes enable dyeing in a wide range of hue from vivid color to deep color and are, accordingly, used for cellulose fabrics as the most consumed dye instead of direct dyes and acid dyes.
For example, JP-A-8-259866 describes an ink jet textile printing black ink that exhibits good color developability for cellulose fabrics and is resistant to clogging of the head. JP-A-2011-84680, JP-A-2015-119297, and JP-A-9-279488 each describe an ink jet textile printing black ink containing C.I. Reactive Black 39 (hereinafter may be referred to as RB 39) as a reactive dye for dyeing fabric black. JP-A-2014-198816 describes an ink jet printing dye ink that is black with good hue and can reduce bronze luster on printed articles.
However, RB 39 used in JP-A-2011-84680 is rather dark blue (a*<0) than black and is not good in black color developability. If the RB 39 content is increased to enhance the black color developability, the ink becomes likely to clog nozzles and thus hinders stable ejection of the ink. Also, if the RB 39 content is increased, the ink becomes likely to attack the material of the cartridge and flow channels of the printer when coming in contact therewith, thereby causing foreign matter to be generated.
Furthermore, if the RB 39 content is increased to enhance the black color developability, the optical density may reach the upper limit thereof, or the reproductivity of the black color may decrease (chroma C* increases). On the other hand, the market demands to adjust the tone of black to, for example, bluish black or reddish black. A technique for easily controlling the hue in an a* direction is desired.